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TRANSCRIPT
DEVELOPING POLICIES FOR RESPONDING TO CLIMATIC CHANGE
A summary of the discussions and recommendations of the workshops held in
Villach (28 September -2 October 1987) and
Bellagio (9-13 November 1987), under the auspices of the Beijer Institute, Stockholm
This report was written by Jill Jaeger (Beijer Institute) based on material pre pared by
W.C. Clark, G.T. Goodman, J. J aeger, M. Oppenheimer and G.M. Woodwell, and contributions from othe r members of the Steering Committee of the project.
WORLD METEOROLOG[CAL ORGANIZATION
'J"- ) ~~ ; D(,\.~ WHO
WC[P .- l
WMO/TD- No. 225
(April 1988)
UNITED NATIONS EN~RONMENTPROGRAMME
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PREFACE
wciP 1 \.D at~
This discussion of the development of policies for responding to climatic change is a result of two workshops which took place in 1987. The first workshop, held in Villach, Austria from 28 September to 2 October, involved about 50 scientists and technical experts (see Appendix I for list of participants). It examined how climatic change resulting from increases of greenhouse gas concentrations in the atmosphere could affect various regions of the earth during the next century. In addition, the participants of the Villach workshop discussed the technical, financial and institutional options for limiting or adapting to climatic changes. The second workshop was held in Bellagio, Italy from 9 - 13 November. The 24 participants (Appendix II) used the technical material from the Villach workshop as background information and explored what policy steps might be considered for implementation in the near term and what institutional arrangements would be needed to achieve these steps.
The two workshops in 1987 were a direct response to the recommendations of an international conference sponsored by the World Meteorological Organization (WMO), the United Nations Environment Programme (UNEP) and the International Council of Scientific Unions (ICSU) held in Villach, Austria in October 1985. Both workshops were seen by the Advisory Group on Greenhouse Gases (AGGG) of WMO, UNEP and ICSU as an important step in the process of policy development in response to possible climatic changes that was called for by the Villach Conference in October 1985.
The project to organize the 1987 workshops was initiated by the Beijer Institute (Stockholm), the Environmental Defense Fund (New York), and the Woods Hole Research Center (Massachusetts).The organization of the workshops and the writing of this document were guided by a steering committee, whose members were:
G.T. Goodman B. Bolin
W.C. Clark
W.Degefu
H. Ferguson
F.K. Hare J. Jaeger M. Oppenheimer C.C. Wallen
G.M. Woodwell
(Beijer Institute, Stockholm), Chairman (International Meteorological Institute, Stockholm)
(International Institute for Applied Systems Analysis, Austria and Harvard University, U.S.A.)
(Meteorological Services Agency, Ethiopia)
(Atmospheric Environment Service, Environment Canada, Canada)
(University of Toronto, Canada) (Beijer Institute and F.R. Germany) (Environmental Defense Fund, U.S.A.) (United Nations Environment Programme, Nairobi)
(Woods Hole Research Center, U.S.A.)
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'.
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The workshops were sponsored by
United Nations Environment Programme Rockefeller Brothers Fund, U.S.A. The German Marshall Fund of the U.S., U.S.A. Rockefeller Foundation, U.S.A. Ministry for Environment, Youth and Family, Austria Energy Research Commission, Sweden Beijer Institute, Sweden W.Alton Jones Foundation, U.S.A.
The organization and running of the workshops benefited from the assistance of Marilyn Brandl, Julian Dison, Lotta Koludrovic, Solveig Nilsson and Mary Stanojevic. Also, the staff of the Villach Congress House and the Bellagio Conference Center helped to make the workshops enjoyable and successful. Professors F.K. Hare (Toronto, Canada) and P. Crutzen (Mainz, F.R. Germany) kindly hosted meetings of the Steering Committee.
In December 1987 the AGGG meeting in Paris reviewed and approved a draft of this Report. Subsequently the Steering Committee reviewed the Report and met in January 1988 to discuss final changes. Finally, Pier Vellinga, Sir Peter Marshall, Jim Bruce, John Firer and Pierre Crosson reviewed a draft version of the Report and provided very constructive criticism. Given the complex nature of the problem and the diversity of interpretations of the present state of knowledge and priorities for action, the suggestions for changes in the report were in some cases divergent. The fact that there are differences in preferred emphasis and interpretation indicates that there is indeed a need, in particular, for policy research, as discussed in section 4 of this Report.
The following sections of the Report summarize the discussions at the 1987 workshops.In Section 1 the scientific consensus on greenhouse gases and climatic change reached at the conference in Villach in 1985 is discussed. This consensus was the starting point for the discussions at the two workshops in 1987. Section 2 looks at possible scenarios for future changes of climate and sea-level. Section 3 examines the effects of possible climatic changes on regions in the high latitudes, middle latitudes, humid.tropics, semi-arid tropics, and coastal zones. In section 4 the management options for responding to the possible changes are discussed. Section 5 looks at a number of factors that might affect policy development and sets priorities for the next steps in policy action based on present knowledge.
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EXECUTIVE SUMMARY
DEVELOPING POLICIES FOR RESPONDING TO CLIMATIC CHANGE
1. The atmospheric concentrations of a number of are increasing as a result of human activities. have an important effect in trapping energy at surface and in the lower atmosphere (the effect'') leading to a warming thus to changes of
trace gases These gases the earth's "greenhouse climate.
2. It is now generally agreed that if the present trends of greenhouse gas (GHG) emissions continue during the next hundred years, a rise of global mean temperature could occur that is larger than any experienced in human history.
3. A two stage workshop process held in Villach (Austria) and Bellagio (Italy) in 1987 examined how climatic change resulting from increasing GHG concentrations could affect environment and society during the next century and explored the policy steps that should be considered for implementation in the near term.
4. Scenarios of global climatic change that could occur between now and the end of the next century as a result of continuing emissions of GHGs were developed. The upper bound scenario, which considers a large increase of GHG emissions and a high sensitivity of the climatic response, gives a global surface temperature increase of 0.8 oc per decade from the present until the middle of the next century. The middle scenario, which considers current trends in GHG emissions, a reduction of chlorofluorcarbon emissions according to the Montreal Ozone Protocol, and a moderate climate sensitivity, gives a temperature increase of 0.3 °C per decade. The lower bound scenario, which assumes a strong global effort to reduce GHG emissions and relatively low climate sensitivity, gives a rate of temperature increase of 0.06 °C per decade.
5. The most extreme temperature increases would probably occur during winter in the high latitudes of the Northern Hemisphere, where the changes could be two to two and a half times greater and faster than the globally averaged annual values. Precipitation changes could include enhanced winter precipitation in the high latitudes, intensified rains in the presently rainy tropical latitudes, and, perhaps, a decrease in summer rainfall in the mid-latitudes.
6. GHG-induced global warming could accelerate the present sea-level rise, probably giving a rise of about 30 cm but possibly as mu9h as 1.5 m by the middle of the next century. The effects of~~ill include: erosion of beaches and coastal margins; land-use changes; wetland loss; increased frequency and severity of flooding; damage to port facilities, coastal structures and water management systems.·
7. In be on
the middle relatively
latitudes the main impacts are expected to unmanaged ecosystems, in particular the
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forests. If the temperature change is rapid, dieback of trees will result and more and more forest would need managing to maintain it in a productive mode. For the lower bound scenario of temperature change, extinction of species, reproductive failure and large-scale forest dieback would not occur before the year 2100. A further effect could be the release of a significant amount of carbon from soils, trees and other plants as carbon dioxide and methane and this would enhance the greenhouse warming.
8. Climatic change will not occur in isolation. Increasing amounts of atmospheric and aquatic pollutants can be expected from urban-industrial growth. The response to climatic change will be affected by these pollutants. The importance of these interactions and the need to investigate them further cannot be overestimated.
9. In the semi-arid tropical regions the climatic changes that might occur by the middle of the next century as a result of the increasing concentrations of GHGs include a temperature increase of the order of 0.3 - 5 oC and a decrease in precipitation rate in one or more seasons.These changes could worsen the c11rrent critical problems of the semi-arid tropics, especially through their effects on food, water and fuelwood availability, human settlement patterns and the unmanaged ecosystems.
10. In the humid tropical regions it is expected that the GHG-induced changes could include a warming of 0.3 - 5 oC and an increase in rainfall amount. In addition, tropical storms might extend into regions where they are now less common. Coastal and river regions and regions of infertile soils in the uplands appear to be especially vulnerable.
11. In the high-latitude regions it is expected that the mean winter temperature could increase by between 0.8 to considerably more than 5 oC by the middle of the next century. In addition, there could be a withdrawal of the summer pack ice, increased cloudiness and precipitation, slow disappearance of the permafrost and changes in the tundra and in the northern limit of the boreal forest. These changes can be expected to affect marine transportation, energy development, marine fisheries, agriculture, human settlement, northern ecosystems, carbon emissions, air pollution, and security.
12. The rate of global temperature change that would occur if current trends of GHG emissions were to continue are large compared with observed historic changes and would have major effects on ecosystems and society. For this reason a coordinated international response will become inevitable.
13. Adaptation strategies for responding to a changing climate adjust the environment or our ways of using it to reduce the consequences of a changing climate; Limitation strategies control or stop the growth of GHG concentrations and limit the climatic change. A prudent response to climatic change would consider limitation and adaptation strategies.
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14. Whatever limits on climatic change might be implemented, planning and decision-making could be facilitated by the use of long-term environmental targets, such as the rate of temperature or sea-level change. The choice of a target would be based on observed historic rates of change that did not put stress on the environment or society. The environmental target can be translated into emissions targets for GHGs that could be used for regulatory purposes .
15. An evaluation of the changes of GHG emissions that would be required to limit the global warming rate to the largest natural rates of increase observed in the last century, suggests that the limitation could only be accomplished with significant reductions in fossil fuel use .
16. Strategies for adapting to or limiting climatic change could involve high costs to global society. For policy-making purposes there is a need for detailed comparisons of the costs of variou~ strategies.
17. There are many longer-term actions that will be required in order to ensure appropriate responses to climatic changes. The actions that should receive priority now are:
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- Approval and implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer.
- Reexamination of long-term energy strategies with the goals of achieving high end-use efficiency .Intensification of development of non-fossil energy systems.
- Strong support for measures to reduce deforestation and increase forested area .
- Development and implementation of measures to limit the growth of non-COz GHGs in the atmosphere.
- Identification of areas vulnerable to sea- level rise. Planning for installations near the sea should allow for the risks of sea-level rise .
- Support for and coordination of policy research, global monitoring activities and policy-directed scientific research on the GHG issue at the national and international levels.
- Examination by organizations, including the inter governmental mechanism to be constituted by the WMO and UNEP in 1988 , of the need for an agreement on a law of the atmosphere as a global commons or the need to move towards a convention along the lines of that developed for ozone.
- Consideration and development of the recommendations of the present Report at subsequent conferences, including the World Conference on the Changing Atmo _ sphere (Toronto, June 1988) and the Second World Climate Conference (Spring, 1990).
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1
Section 1
GREENHOUSE GASES AND CLIMA'r.lQ._.Q_HANGE
1.1 THE "GREENHOUSE EFFECT"
The atmospheric concentrations of a number of trace
gases are increasing. Despite their very low concentrations,
some of these gases, notably carbon dioxide (C02), nitrous
oxide (N20), methane (CH4 ), chlorofluorocarbons (CFCs) and
tropospheric ozone (03), have an important effect in trapping
energy originating from the sun, in the form of heat, near
the earth's surface (the "greenhouse effect"). The increased
concentrations of the "greenhouse gases" (GHGs) lead to a
warming of the earth's surface and the lower atmosphere and
hence to changes of climate.
1.2 THE SCIENTIFIC CONSENSUS ON GREENHOUSE GASES AND
CLIMATIC CHANGE REACHED AT VILLACH IN OCTOBER 1985
During the last ten years scientists have given increas
ing attention to possible future global climatic changes
resulting from this greenhouse effect. It is now generally
agreed that if present trends continue ''in the first half of
the next century a rise of global mean temperature could
occur which is greater than any in man's history" (World
Climate Programme, 1986).
At a joint UNEP/WMO/ICSU Conference held in Villach,
October 1985 (World Climate Programme, 1986), scientists from
29 industrialized and developing countries agreed that:
''Many important economic and social decisions are being made today on long-term projects... such as irrigation and hydro-power; drought relief; agricultural land use; structural designs and coastal engineering projects; and energy planning-all based on the · assumption that past climatic data, ... are a reliable guide to the future. This is no longer a good assumption since the increasing concentrations of GHGs are expected to cause a significant warming of the global climate in the
2
next century."
Furthermore, the participants at the 1985 conference em
phasized that the amounts of the greenhouse gases in the
atmosphere are increasing as a result of human activities and
that the role of greenhouse gases other than C02 in changing
the climate is already about as important as that of C02 . A
further conclusion was that future changes of climate of the
order of magnitude obtained from climate models for a
doubling of the atmospheric C02 concentration could have
profound effects on global ecosystems, agriculture, water
resources and sea ice.
The scientific consensus reached at the Villach Con
ference in 1985 and documented in the Conference Statement
(World Climate Programme, 1986) provided an authoritative
evaluation of the possible magnitude of future climatic
changes resulting from greenhouse gas increases. In addition,
it recommended a start on policy analysis to identify the
widest possible range of social responses for limiting or
adapting to climatic changes.
The conclusions of the 1985 Villach conference were used
as a starting point for the 1987 Workshops on ''Developing
Policies for Responding to Climatic Change". The discussions
and recommendations of these workshops are summarized in the
remainder of this Report.
SOURCES OF INFORMATION
Bolin, B., B.R. Doos, J.Jaeger, and R.A. Warrick (eds.), 1986: The Greenhouse Effect, Climatic Change, and Ecosystems. SCOPE 29, J.Wiley and Sons, Chichester.
World Climate Programme, 1986: Report of the International Conference on the Assessment of the Role of Carbon Dioxide and of Other Greenhouse Gases on Climate Variations and Associated Impacts. WMO-No. 661, World Meteorological Organization, Geneva.
3
Section 2
POSSIBLE SCENA~IOS FOR CLIMATIC CHANGE
In recent years, numerous studies have explored the
potential consequences
changes and possible
of accelerating global climatic
strategies for managing them. It has
increasingly clear that scientific assessments of become
climatic change must address three issues if they are to be
useful for such policy discussions:
a) the rate and timing of climatic changes;
b) the expected changes of regional climates;
c) the uncertainties in forecasts of climatic changes.
A group of the technical experts who convened at Villach in
1987 considered these issues carefully; their findings are
summarized in this section.
2.1 HOW MIGHT THE GLOBAL CLIMATE CHANGE IN RESPONSE TO
CONTINUING EMISSIONS OF GHGs ?
Figure 1 draws on the present understanding of the
greenhouse effect to present a range of scenarios of global
climatic change that might plausibly occur between now and
the end of the next century as a result of continuing
emissions of GHGs. The historical record of climatic changes
since 1850 is included for perspective. In each of the
scenarios the globally averaged temperature is higher during
the next century than it was during the last hundred years.
The middle and upper scenarios also have higher sea-level
during the next century than in the last hundred years, while
the low scenario shows a return to a global sea level of the
order of that observed about one hundred years ago. This
decrease of sea-level is basically a result of a predicted
increase of snowfall which increases the mass of the An
tarctic ice sheet. The resulting loss of water from the
oceans is larger than the direct thermal expansion effects
that would increase sea-level in the
temperat.ure t7
----~---r_·~ ,(: t.f! -~ .. - c (
increase. The intensity r''_-u. {-:'.~' '\! <"( ://. •. /(. ~?"::.~:·~.. ~ ~ ;'~.
(
case of a slow global
of the global hydro-'
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4
FIGURE 1 SCENARIOS OF TEMPERATURE AND SEA-LEVEL CHANGE
The figure shows scenarios of changes in (a) globally averaged temperature and (b) sea-level that might develop in response to continued emissions of atmospheric GHGs. The values are plotted as differences from the 1985 values. Each of the scenarios includes the time lags in the climatic response as a result of the ocean's heat capacity. The middle curve of each panel reflects a scenario of continued present trends of emissions (except for CFCs, see Section 2.2) and a moderate climate sensitivity. There is a chance of 5:10 that the actual path of climate change could lie below the middle curve. The upper curve of each panel reflects a scenario of accelerated greenhouse gas emissions and a relatively high climate sensitivity as predicted by some models. The lower curve of each panel reflects a scenario of radically curtailed GHG emissions and a relatively low climate sensitivity. In the professional judgement of the Villach 1987 experts group, there is a 9/10 chance that the actual future pattern of GHG-induced climatic change will lie within the bounds set by the upper and lower curves. The ceiling of 5 degrees on the temperature graph has been imposed because of the dubious relevance of present climate models in simulating the response to a global warming higher than around 5 degrees. Observed temperature data were provided by P.D. Jones, Climatic Research Unit, University of East Anglia, U.K. Observed sea-level data were provided by V. Gornitz, Goddard Space Flight Center, Institute for Space Studies, New York, N.Y.
(a) Global temperature change (oC).
(°C) 5~------------·--------------·-------T------~
4-
3 -
2 -
1 -
upper scenario (rate 0.8°C/decade)
~ ......
7'
+ .....
middle scenario (rate 0.3°C /decade)
'-. .. ··· ;f'
.·
,,:
~· ..... ~····;/········1 • . ..r- . ....
.!! • .. 7 0 .. ... -:.. .· ;...,:;...~:.~" .. ~"' ... ...;>¥.-r... +· ·. low scenario
"~~~'• ..... ~ • .. ·::_-c-·!* • . (rate 0.06°C/decade) •., ·.~rr•,.*I'X • • •
-1+---~~~~--~--~--~~--~--~--~--~~
1860 1900 1940 1980 2020 2060 2100
years
5
(b) Global sea-level change (cm).
(cm) 150 -.-· ------------------~-
-
-100-
-
-50 -
-
upper scenario . (rate 24 cm/decade)
~/
.J-
+!.
i
.....
middle scenario
(rate 5.5 cm /decade)
~ ....
.~· •'
0 i • low scenario •.-y;./"'" _ • .....,...,. ... _......,Y>"'r. (rate -1 cm/decade)
* -r +'" ....... ·+·..... . . ...... If i - +'
········ ......
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1860 1900 1940 1980 2020 2060 2100 years
mean rates of both evaporation and precipitation, is expected
to increase by 2-3 per cent for each degree of global
warming. In most of the scenarios shown in Figure 1, the rate
of climatic change significantly exceeds the average rate for
the last century. The climatically induced sea-level changes
shown in the Figure would be the same everywhere on Earth,
although they will be affected by local geological (tectonic)
phenomena. The temperature changes, in contrast, reflect the
annual average condi·tion of the world as a whole, not the
conditions at any specific place. Regional changes in
temperature and precipitation are summarized in Table 1, and
discussed in section 2.3. Other factors that might affect
temperature, such as volcanic aerosols and changes of
incoming solar radiation, have not been included. Some
combination of cooling factors seems to have affected global
temperatures during the past half-century, reducing the
greenhouse warming ~nd slowing the rise of temperature and
sea-level.
In constructing the scenarios of Figure 1, allowance has
6
been made for emissions of all the significant GHGs affecting
climate, including the chlorofluorocarbons, (see Appendix 5)
and for time-lags in the climatic response introduced by the
ocean's heat capacity.
2.2 WHAT ARE THE UNCERTAINTIES IN FORECASTS OF GLOBAL
CLIMATE CHANGE?
The wide range of scenarios depicted in Figure 1
reflects two kinds of uncertainty:
1) future patterns of fossil fuel use, rates of deforesta
tion, and other activities leading to GHG emissions;
2) the response of the climate system to a given level of
GHG emissions.
These uncertainties contribute about equally to our overall
uncertainty in forecasting future climatic change. The
envelope of scenarios pictured in Figure 1 has been con
structed so that, in the judgement of the Villach 1987
experts, there is a 9:10 chance that the actual future
pattern of GHG-induced climate change will lie within the
bounds set by the upper and lower curves.
The possibility remains, however, that unanticipated
effects of the warming or unforeseen technologies affecting
GHG emissions could lead to climatic changes outside the
envelope depicted in Figure 1. The speed with which the
atmospheric concentrations of the various GHGs increase adds
a new dimension to the problem: the possible occurrence of
unpredicted changes in biotic, atmospheric and oceanic
responses cannot be ruled out.
The upper bound of the envelope represents the climatic
change that could result from a radical expansion of fossil
fuel use (for example, it is assumed that coal use increases
more than five fold by 2025) and other activities that emit
GHGs, if the climatic response to GHGs exhibits the high
sensitivity now predicted by a few .studies. The lower bound
of the envelope represents the climatic change that could
result from a strong global effort to reduce GHG emissions
(including, for example, a reduction of the C02 emissions
7
from fossil fuels by about half between 1975 and 2075), if
the climatic response exhibits the relatively low sensitivity
now predicted by a few other studies. The middle curve in the
figure shows the climate change that could result from a
continuation of present trends in GHG emissions, if the
climatic response actually exhibits the moderate sensitivity
to GHGs that many climate models now predict. It was assumed
in calculating this curve that the recent protocol on
protecting the ozone layer is successfully implemented, thus
reducing the emissions of CFCs significantly below their
recent rates of increase.
2.3 REGIONAL .RESPONSES TO CLIMATIC CHANGE?
Essentially all scientific studies of the greenhouse
effect agree that the resulting climate changes will differ
among regions. Uncertainties in the forecasts of regional
climatic responses are greater than those in the forecasts of
global climatic response. Present knowledge of possible
regional climatic changes is summarized in Table 1.
Table 1 suggests that the most extreme temperature
increases in a warming world would probably occur during
winter in the high latitudes of the Northern Hemisphere.
Changes here could be two to two and a half times greater and
faster than the globally averaged annual values shown in
Figure 1. In contrast, temperature changes in the low
latitudes will probably be somewhat smaller and slower than
the globally averaged values of Figure 1.
Regional precipitation forecasts are the most uncertain
of all the major climatic variables. Nonetheless, the
studies used to derive the information in Table 1 suggest
that changes could include enhanced winter precipitation in
the high latitudes, intensified rains in the presently rainy
low latitudes and, perhaps, a decrease in summer rainfall in
the mid-latitudes.
8
SOURCES OF INFORMATION
Material in this section was based on Background papers prepared for the Villach Workshop (listed in Appendix 7). In addition, reference was made to:
Gornitz, V. and S. Lebedeff, 1987: Global sea-level changes during the past century. In, D. Nummedal, O.H. Pilkey, and J.D. Howard (eds. ), Sea Level Change and Coastal Evolution. Society of Economic Paleontologists and Mineralogists Publ. No. 41, 2-16.
Hansen, J., A. Lacis, D.Rind, G. Russel, P. Stone, I. Fung, R. Ruedy, and J. Lerner, 1984: Climatic sensitivity: Analysis of feedback mechanisms. In, J.E. Hansen and T. Takahashi (eds. ), Climate Processes and Climate Sensitivity,Maurice Ewing Series No. 5, American Geophysical Union, Washington D.C., 368 pp.
Jones, P.D., T.M.L. Wigley, and temperature variations between 430-434.
P.B. Wright, 1986: Global 1861 and 1984. Nature, 322,
Manabe, S. and R.J. Stouffer, 1980: Sensitivity of a global climate model to an increase of C02 concentration in the atmosphere. J. Geophys. Res., 85, 5529-5554.
Mintzer, I.M., 1987: A matter of degrees: The potential for controlling the greenhouse effect. Research Report No. 5, World Resources Institute, Washington, D.C.
Mitchell, J.F.B., C.A. Wilson, and W.M. Cunnington, 1987: On C02 climate sensitivity and model dependence of results. Quart. J. Roy. Meteor. Soc., 113, 293-322.
Nordhaus, W.D. and G.W. Yohe, 1983: Future paths of Energy and Carbon Dioxide Emissions. In, Changing Climate, Report of the Carbon Dioxide Assessment Committee, National Academy Press, Washington, D.C.
Reilly, J.M., J.A. Edmonds, R.H. 1987: Uncertainty analysis of the model. The Energy Journal, 8, 1-29.
Gardner, A.L. Brenkert, IEA-ORAU C02 emissions
UNEP, 1987: Montreal Protocol on Substances that Deplete the Ozone Layer. Final Act. United Nations Environment Programme, Nairobi.
10
Section 3
EFFECTS OF CLIMATIC CHANGK_ON THEJL~TITUDINAL REGIONS
3.1 OCEANS AND COASTAL AREAS
Half of humanity inhabits coastal regions. The coastal zones are under great pressure due to accelerating population growth, pollution, flooding problems and upland water diversion.
In these regions the consequences of sea-level rise will generally outweigh any direct ·temperature effects of climatic change, such as enhancement or reduction of fishery resources. In particular, a rise of sea-level would, in many places, mean that high tides could penetrate further inland. In addition, the effects of rising sea-level would be experienced in terms of greater inland penetration of storm surges.
Global warming induced by greenhouse gases will accelerate the present sea-level rise giving a rise of probably about 30 cm and possibly as much as 1.5 m (see Fig. lb) by the middle of the next century, as a result of thermal expansion of the sea-water and the melting of land ice. The rate of increase of sea-level could therefore be appreciably greater than the 0.01 m per decade long-term average for the last century.
The effects of sea-level rise will include:
Erosion of beaches and coastal margins: some 70 per cent of the world's beaches are presently eroding due to a combination of natural sea-level rise and human intervention. This process will be aggravated by the sea-level rise induced by global warming. For example, the cost of maintaining shores under threat on the East Coast of the USA will be of the order of 10-100 billion US dollars for a one metre sea-level rise.
Land-use Changes: decrease of usable land for various aspects of primary production, including aquaculture ,and for activities such as salt-making arises from the joint effects of subsidence due to river modification and sea-level rise. It is generally counteracted by dykes and other diversions. Where counteracting measures are not feasible, ·these changes can lead to large land and livelihood losses. In developed countries, lowland protection against sea-level rise will be costly. In developing countries without adequate technical and capital resources, it may be impossible.
Wetlands loss: natural wetlands are now under pressure: urbanization encroaches on salt marshes; mangroves are harvested or displaced by fishponds etc. In the natural state, wetlands adjust to sea-level increases by moving landward- a process that is inhibited by steep coastlines and human made structures. Where migration has become impossible, wetlands will be lost, with associated losses of natural resources, habitat and physical barriers against flooding.
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Frequency and severity of flooding: a projected sea-level rise of as much as 1.5 m. within 75 years would cause many flood disasters, with large losses of life, property and farmland, particularly in the delta regions of South Asia. Damage to infrastructure in the industrialized countries would also result.
Damage to coastal structures and port facilities: sea-level rise will increase the hydraulic loading on coastal structures like breakwaters, locks, and bridges. Reinforcement. will be required and maintenance costs will increase. Port facilities will have to be adjusted to a higher sea-level.
Damage to water management systems: sea level rise will also cause problems with drainage and irrigation systems. Saltwater intrusion into groundwater, rivers, bays, and farmland will increase. This will create a demand for reconstruction and extension of water management systems and structures, which may not always be economically feasible. To give an example of costs, in the Netherlands, a country that already has a finely-tuned coastal defences infrastructure, the Public Works Department has tentatively estimated that the minimum adjustments to the water management systems there for a lm sea-level rise would require additional investments of the order of several billion dollars.
3.2 MID-LATITUDE REGIONS
In the middle latitude regions between 30 and 60 degrees
latitude, the amount of warming caused by increasing GHG
concentrations will be greater than the global average
warming (Table 1). Additionally, the winter temperatures are
expected to increase more than the summer temperatures.
Changes in precipitation and soil moisture are uncertain,
although soil moisture in summer could decrease as a result
of enhanced evapotranspiration with the increased tempera
tures. The effects of climatic change on agriculture, water
resources and soils have been considered but the most
important effects. _ _§!,_J;'e expected to be __ on_ rel_q_ti vely_JJ_nmanaged
eQOSYs.:temB., especially forests. Two aspects of the global
climatic changes
ecosystems:
are particularly important for these
0 future climatic changes are likely to be much more
rapid than those in the past;
0
12
in the absence of measures to limit GHG emissions,
the climate will continue to change and the changes
will persist indefinitely into the future.
Forests: The forests of the middle latitudes contain, in trees, other plants and soils, a quantity of carbon that is comparable in magnitude to the amount of carbon currently stored in the atmosphere. The effects of the climatic changes anticipated include the possibility of the release of a significant amount of carbon from this source into the atmosphere as carbon dioxide and methane, which would further increase the greenhouse warming.
The possible responses of mid-latitude forests to climatic change have been assessed, taking into consideration the rate of seed migration, changes in reproductive success with changes in temperature, and climatic stress on standing trees (see Appendix 6). The reproductive success of many tree species would be reduced by a warming and both tree and plant mortality would increase. These changes would be conspicuous first along the warmer and drier limits of the range of the species. There is no threshold below which effects do not occur.
The upper limit of the climatic changes shown in Figure 1 suggests a rate of warming of 0.8-1.0 oC per decade in the middle latitudes. Major effects on forests were estimated to begin around the year 2000 with forest dieback starting between 2000 and 2050. The net effect of the warming would be a reduction in area and standing stock of carbon in forests. The seriousness of the changes depends on the rate of change of temperature.
For the lower bound of the temperature scenario, which gives an average rate of change of mid-latitude temperature of 0.06 - 0.07 oC per decade, extinction of spe6ies, reproductive failure and large-scale forest dieback would not occur before the year 2100, although the warming would cause some changes in the forested regions. However, with the rates of temperature change of the lower scenario the changes in the forested regions would be at rates that are low enough to approximate to the rates at which forests have accommodated to climatic changes observed in the recent past.
These estimates illustrate the importance of the rate of change of temperature for the effects on forests. If the temperature change is rapid, dieback of trees will result, with replacement of successional trees supporting smaller standing crops. The outcome of this trend would be that more and more forest would need planting (or managing) to retain it in a productive mode. Such labour-intensive intervention may be economically non-viable for formerly unmanaged forests.
Agriculture: warming will cause intra-regional shifts in productivity in the mid latitudes. For all but the most rapid warming, adaptation based on agricultural research should
13
permit maintenance of total global food supplies. However, there will be local disruptions. For the faster rates, agricultural adaptations may be out of step in time with effects of climatic change, generating erratic reductions in food availability. Taken alone, climatic warming would have probably little pe~ effect on agriculture in the mid-latitude band: productivity in the lower-latitude zone of th~ band might be negatively affected because of increased evapotranspiration, while the higher latitudes of the band would benefit from the longer growing season. Agriculture is dependent on the availability of fertile soils. Shifts of crops due to GHG-induced climatic changes may be affected positively or negatively by this factor. There are also major uncertainties about changes in precipitation and evapotranspiration, so that it is not possible to predict at this stage whether the net effects of change will be positive or negative for specific regions except that irrigated agriculture in semi-arid areas in the mid-latitudes will probably be adversely affected by the warming.
Interacting Effects: climatic change will not occur in isolation. Increasing amounts of atmospheric and aquatic pollutants can be expected from urban-industrial growth. The response to climatic changes will be affected by these increased pollutants. The ____ i..nmort_a:qce of the~§_interacti_Qll.§_ .and the ~ecL._to ___ inve.~a.:ti_gg:t§_ them ___ fur..t_ber __ cannQj;._ __ be .QY.§.rE~m-
_pha§..i~eg. Such interactions are now causing widespread mortality of many species of coniferous and broad-J.eaved trees in Europe and in eastern North America.
3.3 THE SEMI-ARID TROPICAL REGIONS
The semi-arid tropical regions lie within the broad
latitudinal band 5-35 oN and S. Within this zone the semi
arid and sub-humid regions are defined as areas receiving
mean annual precipitation
lOOOmm, unevenly distributed
and interannual variability.
somewhere within the range 400-
seasonally, with high spatial
Climatic variability is a problem for the semi-arid
tropical regions. Any future changes in the frequency
distribution of extreme events will have important effects.
The climatic changes that might occur by the middle of the
next century as a result of the increasing concentrations of
trace gases in the atmosphere include:
0
0
Increases of regional temperature of the order of 0.3-5 oC.
On average for the latitudinal belt as a whole, climate model results are variable, but a tendency
14
for a decrease in precipitation rate in one or more seasons is generally apparent. In addition, temperature increases would reduce soil moisture availability.
The semi-arid tropical regions already suffer from seasonal and interannual climatic variability. Precipitation data for the zone 5 - 35 oN show a pronounced downward trend since the early 1950s, resulting in prolonged drought and active desertification processes. These regions are very sensitive to climatic variability, generally with negative impacts. Therefore, future climatic changes could worsen the current critical problems of the semi-arid tropics. The major effects are expected to be on:
Food availability: temperature increases, precipitation pattern changes and C02 concentration changes would alter the agriculture and agricultural production potential within a region which is already highly sensitive to the impacts of climate and often marginal for agriculture. Productivity changes could aggravate current difficulties in meeting basic nutritional needs. Resource degradation through increased desertification could ensue.
Water Availability: in general, evaporation would increase and runoff would be reduced. Water availability would be further reduced by increased demand.
Fuelwood Availability: changes in biomass productivity and soil moisture will probably lead to reduced fuelwood availability.
Human Settlement: as agricultural and resource potential changes, human populations are expected to move in responseincluding increased rural-to-urban migration.
Unmanaged Ecosystems: climatic changes and human responses are expected to increase pressure upon unmanaged ecosystems and heritage sites. Biotic resources will be stressed by habitat changes and development pressures.
3.4 THE HUMID TROPICAL REGIONS
By the middle of the next century it is expected that
the addition of C02 and other trace gases will warm the humid
tropical regions by 0.3-5 degre~s C. This warming, somewhat
less than the global average warming, will be accompanied by
an increase in rainfall amount, perhaps in the range of 5-20
per cent. In a region that is already often too hot and too
wet, even such relatively modest climatic changes could have
15
important effects. The increased rainfall may occur largely
through increases in rainfall intensity. Superimposed on
these general tendencies would be shif.ts _,in the g~r@b_:hcq_l
patterns of ~9infall and cloudipes~. Since, the warming will
increase potential evapotranspiration, there could be a
tendency toward more drought __ stress in many, if not most, of
the regions in the humid tropics. With the increased ocean
temperatures tropical storm§ might extend into regions where
they are now less common. Where they already occur, increased
intensity of winds and rainfall might be expected.
The major effects of climatic changes would there
fore result from:
0
0
Rising water levels along coasts and rivers, resulting from a combination of increasing sealevel, greater chance of tropical storm surges and rising peak runoff. These will result in larger areas being subject to flooding and a risk of salinization.
Changing spatial and temporal distribution of temperature and precipitation with effects on industry, settlement) agriculture, grazing lands, fisheries and forests.
Two provinces of the humid tropics appear especially vul
nerable to the kinds of climatic change that may occur over
the next century:
o coastal and river regions subject to changes of sealevel and storminess;
o regions of infertile soils in uplands.
3.5 HIGH-LATITUDE REGIONS
The high-latitude areas include regions north of 60 oN
and south of 60 oS. The effects discussed here are those that
could occur in the northern high latitudes.
The magnitude of expected climatic changes
By far the largest changes would occur in winter
(Table 1). As a result of increases of GHGs, it is expected
16
that by the middle of the next cen·tury the r!lean-'dinte.h
~em~~+at~K~ of this region could increase by 0.8 to con
siderably more than 5 oC by the middle of the next century.
The following effects are the most important:
0
0
0
0
Changes of t,he p.ru;JL.iC~_Q_Q.Dd~t_ioQ.JJ could be very great. A warming could result in the withdrawal of summer pack-ice, leaving the Arctic ice-free around Spitzbergen and along the north Siberian coast. Loss of pack-ice would significantly decrease the proportion of incoming solar radiation that is reflected back to the atmosphere (albedo), which is the reason for the enhancement of the warming effect in these regions.
There would most likely be .iu.ct:.eased cloudiness ...Qnd _...P..:r.§.ci_pi tg_tion in the high latitude regions of the northern hemisphere. Because of the penetration of moisture-rich, warm air into higher latitudes, the precipitation would increase more than evaporation in high latitudes. Thus the rate of runoff into the Arctic Basin would increase markedly. In the 60-70 N region, duration of snowcover would be shorter.
P~rmafrQ§t, particularly in northern Canada and Siberia would slowly disappear.
Changes in the tundra and in the ~orthern limit of the bo~~~l __ !9rest will include both a stimulation of growth and carbon fixation and rapid decay of organic matter. The overall effect on carbon storage is not predictable. The possibility exists for a large net release of carbon from soils to the atmosphere as a result of increased respiration.
Changes of Arctic pack ice (including decreased albedo)
could have major implications
lower latitudes. In the absence of
for the climatic changes in
the pack ice there would
be changes
would cause
of the atmospheric and oceanic circulations that
climatic anomalies in high, middle and low
latitudes. The potential magnitude of these anomalies is not
known at present.
Given the above potential changes, the following
effects may be expected:
17
Marine Transportation: the possible changes of sea-ice offer opportunities for increased use of the Northeast and Northwest passages. However, prediction of route enhancement is complicated by inadequate understanding of expected changes of ocean currents, cloudiness, fog, ice fields, and icebergs.
Energy Development: higher temperatures and a reduction of sea-ice could reduce some of the difficulties of offshore oil development, but onshore development could become more difficult and expensive in regions of melting of permafrost, affecting construction practices and existing developments. A reduction of sea-ice extent could lead to higher snowfall over the land surrounding the Arctic Ocean, making operating conditions more difficult.
Marine Fisheries: different marine ecosystems could be affected positively and negatively by the increased atmospheric and oceanic temperatures. Useful predictions of the effects on fish migration and species distribution will require further research.
Agriculture: is practised in Scandinavian countries north of BOo N. At present however, its importance, as in other circumpolar countries, is small. With warming, agricultural opportunities should improve, but only over limited areas because of lack of suitable soils. Current food-market conditions make it unlikely that extreme northern areas would ever be exploited for the international agricultural markets.
Human Settlement: climatic warming will make northern mines, forests and ports more exploitable as growth centres. Opening of the Arctic to shipping will increase the cultural shock which has already stressed native peoples. Warmer climates will induce migration into some areas, putting native peoples at risk of losing traditional cultures and environmental values.
Northern Ecosystems: the changes of precipitation, temperature and sea-level will affect the natural ecosystems. Rapid shifts in growth conditions could cause dislocation or disruption of ecosystems as well as movement of the limits of agriculture and forestry northwards.
Carbon Emissions: Nordic regions are important in the global carbon cycle. It has been suggested that the climatic warming could result in a substantial increase of methane emissions from tundra, thus increasing the emissions of GHGs into the atmosphere. Siberian and other boreal soils are often highly organic and would rapidly decay upon withdrawal of permafrost, if they subsequently dry up, thus increasing C02 l~ading to the atmosphere.
Air Pollution and Acid Rain: Arctic haze (already circumpolar) and acid deposition in nordic regions would be affected by climatic changes. The result could be a shift of the region subject to acid deposition, particularly if atmospheric circulation patterns change. There could be a
18
significant degradation of some aquatic and terrestrial ecosystems and perhaps an improvement of others. The importance of these interactions and the need to investigate them further cannot be overemphasized.
Security: the northern ice-bound land borders of North America, Europe and Siberia are highly sensitive national defence zones for all states with Arctic territory. If these coastlines become navigable, fundamental security readjustments will be required.
SOURCES OF INFORMATION
This section the Villach the workshop ted by:
is based on the reports of the Working Groups at workshop, on the background papers prepared for (see Appendix 7) and the keynote papers presen-
E.F. Roots on "The response of the Nordic Areas to climatic change";
G.M. Woodwell on "The warming of the indust.rialized middle latitudes 1985-2050: Causes and consequen ces. ";
P. Crosson on "Climate change and mid-latitudes agriculture: Perspectives on consequences and policy responses.";
J. Mabbutt on "Issues raised by future climatic change in semi-arid tropical regions";
H. Sternberg on "The humid tropics - the case of Amazonia";
,J. Bardach on "Global warming and the coastal zone".
Information on precipitation changes in the semi-arid zones was obtained from:
Bradley, R.S., H.F. Diaz, J.K. Eischeid, P.D. Jones, P.M. Kelly, and C.M. Goodess, 1987: Precipitation fluctuations over Northern Hemisphere land areas since the mid-19th century. Science, 237, 171-175.
Uj
Section 4
EES.PQND1N<I. _'l'Q __ .C.LJJ1A'I.'J.C ___ CHANG.E
4.1 CLIMATIC CHANGE: ADAPTATION AND LIMITATION
As the previous sections have shown, the increasing
concentrations of GHGs could cause climatic chan~es within
the next half century with ma.ior imp1 i<:~ationf.i for environment
and ~.ooc.iety. For this rea:::-;on it, :is necessary to consider
strategies for responding to climatic change. These strat
egies fall into two categories. Adaptation strategies adjust
the environment or our ways of using it to reduce the
consequences of a changing climate; Limitation strategies
control or stop the growth of GHG concentrations in "the
a~nosphere and limit the climatic change. As discussed in the
following section, adaptation c~an be subdivided into "an--
ticipatory" adaptatj_on" and "forced adaptation". A prudent
response to climate change would consider both limitation and
ad[iptat.ion strategies. In fac·L, even if a very concerted
effort were made now to limit emissions, some adaptatior1
would still be necessary. This is because of the climatic
changes, forced by GHG-producing human activities during the
recent decades, that may already be underway and also by
those that would occur before the limitation strategy had
become effective.
Constraints on Adaptation to Climate Change Anticipatory adaptation will involve large expendi
tures. Measures to adapt to climatic change may occur on a
variety of scales, at different times, and with widely
different costs. Some environmental modification measures,
such as changes in coastal defences and freshwater supply
systems, require large investments in infrastructure begin
ning decades in advance of anticipated climatic effects. On
the other hand, many adjustments will consist of behavioural
changes at the individual level occurring in immediate t'
response to perceived climatic or sea-level changes, with
20
little advanced planning. These include changes in diet and
physical activity, as well as some cropping practices and
changes in habitation. Certain adaptation measures occurring
gradually as climate changes will require anticipation but
not as much as that required for hydrological planning. For
example, agricultural research on new crop varieties should
begin in advance of large climatic change but does not
require massive investments decades ahead.
It has been estimated that a partial adaptation to
the increases in sea-level which would occur in the next 50
years as a result of the GHGs already emitted would involve
global expenditures of the order of tens of billions of US
dollars, over a planning and construction time of twenty to
forty years to produce a solution that would be only tem
porary as the climatic change continued. These measures
include construction of sea walls, dykes and drainage
systems, as well as other aspects of coastal maintenance. The
best estimate for sea level rise over the past century is
12cm, about one-fifth of the projected rate of Bern per decade
for the next century if emissions growth continues at current
rates (middle scenario, Figure 1).
The ability of societies to manage such changes is
highly variable. Current coastal flooding in South Asian
deltaic regions results in substantial annual loss of life. A
combination of sea-level rise and local subsidence over the
next century could flood an area of Bangladesh where between
eight and twenty-four million people now reside.
Agricultural research has permitted the adaptation
of production to a large range of soil and climate condi
tions. However, at the upper end of the projected rate of
warming (about 0.8 degrees C per decade globally, Upper
Scenario Figure la); research capabilities may be severely
tested and adaptations may lag behind the rate of climate
change.
Changes in agricultural practices at farm level·will
include substitution of thermal and moisture stress resistant
varieties, alterations in fertilizer application, water use
efficiency investments, and improved drainage to reduce
erosion. At the national level, governments could ease the
21
impact of warming by maintaining an institutional capacity
for flexible response, particularly in agricultural research
and in trade policy. But other policy decisions will require
longer planning horizons. These include land use and water
management decisions, improvement of food storage and
distribution systems, as well as famine identification and
assistance plans.
Natural ecosystems will not adapt effectively to
rapid climatic change. Inland migration of wetlands may be
facilitated at some locations by reserving open coastal land.
With regard to forests, habitats for plants and animals
cannot be re-created or transplanted rapidly. Continuing
climatic changes would strain the capabilities of managem~nt
practices even in commercial tree plantations.
Constraints on Limitation of Climate Change
If GHG emissions continue to increase at current
rates, the global temperature increase in the next century
would be about 0.3 oC per decade (middle scenario, Figure 1).
Whatever limits on climatic change might be implemented, some
procedural mechanism is needed to guide planning and dec
ision-making. In this regard, the use of long-term environ
mental targets, such as the rate of temperature change or
sea-level change, would be extremely advantageous as a
management tool. Such environmental targets would be based on
observed historic rates of change of temperature or sea
level, and on expected consequences for ecosystems and
society. Given a rate of change as a target, it should be
possible to translate this into emissions targets for
greenhouse gases that could be used for regulatory purposes.
Such target rates of change could be supplemented with
absolute limits on temperature which capture other features
of the environmental response to climate, since unlimited
warming at any rate must sooner or later become problematic.
For instance, mid-latitude forests may experience
dieback of standing trees and replacement of canopy trees
with successional species for rates of temperature change
around 0.3 oC per decade (middle scenario, Figure 1). Such
consequences should not affect forests generally and will
r) ') LJ.:...
occur more slowly over the next century for rates of tempera
ture increase of about 0.1 cC/decade and will be partially
accomodated by changes in species and by expansion of forests
into new land. Furthermore, historical experience of in
dustrial societies coping with sea-level rise is restricted
to a period •when warming rates remained near 0.1 oC per
decade or less and sea-level rise was limited to 2 - 3 cm per
decade.
Constraints on the limitation of GHG emissions to
keep the rate of temperature increase below 0.1 oC per decade
may be judged by examining the sources of the individual
GHGs. The middle scenario in Figure 1 already takes into
account the reduction in CFC production required by the
year 2010 under the recent Protocol on Substances that
Deplete the Ozone Layer. This is estimated to lead to a 15-25
per cent decrease in the rate of temperature rise. The
development of substitutes for CFCs may lead to the elimina
tion of emissions of these chemicals. Although uncertainties
are substantial, growth in tropospheric ozone, methane and
nitrous oxide concentrations in the atmosphere will be partly
governed by increases in fossil fuel use and may be limited
in part with available air emissions technology.
Emissions of the non-C02 trace gases will contribute
about one half of projected warming over the next fifty
years, if current trends continue. The sources of these gases
are widely distributed around the globe and certainly not
easy to limit. However, it has been estimated that it may be
feasible to cut this contribution by somewhere between one
half to two-thirds with current technology.
If other conditions of the middle scenario of Figure 1
held, such reductions in non-C02 trace gases would reduce the
rate of warming to ea 0.2 oC per decade. In order to achieve
a target warming rate of 0.1 oC per decade, a reduction of up
to two-thirds in the rate of increase of C02 concentrations
in the atmosphere would still be required. The current
contribution from fossil fuel combustion amounts to about 5
Gigatons (Gtons) carbon per year. Current additions from
deforestation contribute at least 1 Gton per year (and
23
perhaps considerably more) if the carbon uptake by the oceans
amounts to at least 50-60 percent of the emissions. If
deforestation can be significantly reduced, a decrease in
fossil fuel emissions to 2-3 Gtons per year would approach
the target warming rate. Experience with the response of the
atmosphere to these emissions changes will help define long
term policies.
There are basically five options for achieving C02
reductions in spite of continued population growth, and in a
manner consistent with continued economic expansion:
1) .'-L .. K_~quQ__tj_on _ _Q;f_fossU fue_l_g_;se _ ___t_hr_9_\d15h-1J1g.J:.eq,§e§_Qf
.§nd-use ..... flJH~I:Et.Y_ ... effj,_gj.e.nQY. Efficiency advances are
also technically feasible in generation and trans
mission. In the opinion of several respected
analysts, consumption of energy in industrialized
nations could be reduced by fifty percent with
available technology. This could be achieved at
about one percent per year with no strain on GDP
growth. Greater rates are feasible and many ef
ficiency improvements could be achieved with net
economic savings.
2) R§lli_a ~--f os ~j_l ___ f.1J...§l. ___ Q_Q.ffipu s t.i orl._ .. ..wJ .. tJ:L .... _CJ.Jj;._{i;r..!}._g,t..i v e
.sm_el-:_gy _ _§_QQrQ.§§. This strategy is the only viable
long-term approach to offset the consequences of
continued population and economic growth. Available
options include solar energy, wind energy, hydro
electric power, nuclear power, tidal energy and
ocean thermal conversion. Judgments on local
availability and environmental consequences will
govern particular decisions on the energy mix. The
development of a suitable carrier medium for energy
storage and transport would speed the penetration of
these alternatives. Research on the efficacy of
hydrogen gas as a carrier is underway. The early
construction of production and storage facilities
for hydrogen could stimulate the penetration of
alternative technologies and avoid dependence on
C02-rich synthetic fuels.
3)
4)
5)
24
Reverse the current_def_Qre_p_tati_Q..[Lll§J!Q. Elimination
of net forest loss would reduce the amount of fossil
fuel reduction needed. Deforestation contributes to
atmospheric increases in the other trace gases as
well (CFCs excepted).
Large-scale ~forestation has a limited
potential to slow down C02 increases in the atmo
sphere and buy time to reduce fossil fuel emissions.
Shift the :fossi 1 fuel us.sL...mix .f.rom high tq ___ l._gw_ C02-
emitting fuels. The C02 emissions per unit energy
differ according to fuel type; the lowest emissions
per unit energy are from natural gas (0.43 Gt carbon
per TWyr, see Appendix 4 for definition of TW),
followed by oil (0.62 Gt carbon per TWyr), coal
(0.75 Gt carbon per TWyr).
Dispos~Q..L__QQ2 in th~ de~9cean. In principle, C02
from large stationary sources can be removed from
the flue gas and transported to the deep ocean. For
example, thermal power plants account for about
fifteen percent of C02 emissions currently. Ninety
percent removal of C02 and subsequent disposal may
double the cost of producing electricity. Such costs
are of the same magnitude as current pollution
control requirements in several countries.
Global Energy Use
Th.§._l im:l.t.a t ion ......QL.g.l_ o b;;:t.l __ w at:mi ng ..,tg __ Q .... L.JiM.t:§ e s per
G.siQ.9..9....§ cqJJ.lQ._~JCCQmP.lish_ed __ only __ wi th significant reduction.s
.in _ _f_Q.§_pil_f1lel.. .. JJJ2..§. If reasonable economic growth rates are
to be maintained, these reductions can be achieved only with
two major changes: large efficiency increases of the order of
one-half in industrial nations; and rapid deployment of
alternative energy sources. The former goal appears to be
achievable with current technology, The latter goal would
require expanded research
For instance, the World
and development of alternatives.
Commission on Environment and
25
Development has discussed growth in primary energy consump
tion from 10.3 Terawatt years per year in 1980 to about 20
Terawatt years per year in 2025, which allows modest per
capita energy growth in developing countries but does not
allow growth of per capita consumption in industrialized
countries. About 16 Terawatt years per year of this total
would be supplied by fossil fuels, if no penetration of
renewable energy sources is assumed. Even if efficiency of
generation and use of fossil fuel energy were doubled, as
much as 5 Terawatt years per year of fossil fuel consumption
would still need to be shifted to renewables to attain the
target warming rate. This projection assumes t,ha·t the
contribution of deforestation to atmospheric carbon dioxide
will become insignificant.
4.2 THE USE OF RATES OF CLIMATIC CHANGE AS A MANAGEMNENT
TOOL
The goal of 0.1 °C per decade was selected after
considering the observed limited ability of natural ecosys
tems and societies to adapt successfully to faster changes.
The chosen rate is of the same order as recent historical
variations. As illustrated in section 4.1, the setting of a
goal makes it possible to calculate the rates of emission of
trace gases that would be permitted globally in order to
achieve a warming rate at the target level. It also permi t.s
comparison of strategies for achieving the target through
limitation of the different greenhouse gases. Clearly, a
great deal of careful analysis will be required before a firm
global environmental target can be agreed upon. In addition,
even with a long-term environmental target, an adjustment
process in reaching this target will be required and interim
targets would have to be set. Since at the present it is
obvious that the developed countries have greater pos
sibilities for controlling emissions, it might be appropriate
to set different interim emissions goals for the developed
and developing countries. The interim target might also have
to be periodically adjusted to take into account the changes
in scientific knowledge, the introduction of new technologies
26
and the time required to do this, and changing perceptions of
the nature of the problem. In addition, the interim targets
must be justifiable in terms of the estimated costs of
achieving the required emission goals.
4.3 THE TIMING OF RESPONSES TO CLIMATIC CHANGE
Uncertainty and surprise: Global mean temperature has risen
about 0.5 oC over the last century and sea level has risen
about 12 cm. Current atmospheric levels of GHGs may already
have committed the world to an additional 0.5 oC of warming,
and an additional 10-30cm of sea-level rise over the next
f i f t Y Ye a r s , .§.Y_E:?.IL ____ j,_f __ j:JJS?. ___ SJ.___'tffiQ_:;)_p_h§.X i_g ________ Q.QD.l_RQ_$ i_t_iQJL_W e}o·_g
~.t_<::tL)_iJi~-~d _____ _iJrliJ:@Qi.9J:,eJ__y. Consideration of some adaptation
measures appears to be inevitable, and in fact some measures,
such as beach restoration, have already been undertaken.
On the other hand, continuation of growth in the
concentrations of atmospheric trace gases could lead to
unmanageable consequences for coastal zones, forests and, in
specific areas, for the agricultural sector, since the rate
of global mean temperature increase could possibly approach
0.8 oC per decade over the next century (Upper scenario, Fig.
la). In some areas, forest and coastal ecosystems currently
suffer severe stress due to air pollution, and land and water
misuse by humans. Th~s>-~- __ f:l_~;i._q__t __ ,Ln_g __ p_:r_QPLE":;_l]g; ____ wi __ lJ __ J~LEL_Q9mP_Qurfded Q.y __ gl;i,m§t:t_:Lq_ ___ g_b.£t_g_g§.
Furthermore, our understanding of the atmosphere and
the oceans and natural ecosystems is limited and the poss
ibility exists that wholly unforseen changes will occur which
are large and abrupt enough to overwhelm our adaptive cap
abilities and far exceed natural rates of change in ecosys
tems. The sudden deepening of the Antarctic ozone hole over
the last decade exemplifies such a surprise. The likelihood
of surprise increases as climate deviates from historical
bounds.
Timing of Measures: The timing of initiatives to limit
and adapt to climatic change is critical from both an
environmental and a financial perspective. It would be
27
inappropriate to postpone action until the consequences of
warming, which lag behind emissions, are clearly visible.
Policy actions already implemented or under consideration for
other reasons could limit or mitigate the consequences of
warming. For example, energy conservation measures since the
1970s have materially slowed the
atmospheric C02 concentration.
rate of increase of the
In addition, a gradual
reduction in carbon dioxide and other emissions over the next
fifty to seventy-five years has quite different warming
implications than a rapid reduction, particularly with
reference to the magnitude of the cumulative global warming.
4.4 THE COSTS OF RESPONDING TO CLIMATIC CHANGE
If current perceptions about the range of possible
harmful environmental and socio-economic effects (outlined in
Section 3) are substantially correct, then the costs incurred
by doing nothing about climatic change would be large.
However, strategies for adapting to climatic change or
limiting it by controlling greenhouse gas emissions, or both,
could also involve high costs to global society.
Clearly, it would be preferable to be more certain about
the magnitude and rate of onset of global warming and about
its environmental and socio-economic effects before taking
expensive adaptation and/or limitation actions. In addition,
for policy-making purposes there is a need for detailed
comparisons of the costs of various strategies. What kind of
approach and process could provide estimates of such costs ?
Developing a useful framework will pose major challenges to
existing methods of economic and policy analysis. A major
problem is the current practice of "discounting" the future,
since it is inappropriate to discount into present monetary
values the risk of major transformations to the world of
future generations. Likewise, much is lost by using single
numbers to combine the effects of, for example, flooding an
island with the costs of providing irrigation to an arid
region in North America. Methods are needed that build on the
28
best of risk-benifit analysis and intergenerational equity
studies, in order to take into account the complex character
of long-term, large-scale effects of climatic change.
Some of the items that must be included in any scheme
for comparing the costs of different strategies are shown in
Figure 2. The figure considers three scenarios : Business as
Usual; Moderate Effort; and Concerted Effort. The scenarios
are distinguished by the level of effort and ambition of
policies undertaken explicitly to deal with climatic change
induced by greenhouse gases. Steps that limit greenhouse gas
induced climatic change bt1t that are undertaken for other
reasons (e.g. to protect the stratospheric ozone layer) are
not considered.
The Scenarios In the ___ B.g_pil}_~_§.t;L __ _g_§_t;f_§.l,.}_§j,_ scenario, no policies
explicitly directed at greenhouse gas limitation are under-
taken. tJ_g_.Q._era·t§.. ____ __Ef_f_g _ _:rt_§. and ~~9.D..Q.§.J::.:t_~ __ g __ E.f_f_g_;rJ,§. reflect, the
level of effort devoted to energy policy (energy end-use
efficiency and renewable energy sources) , deforestation and
greenhouse gas reduction strategies. The Sux_p_l;:..i.§.Q scenario
differs from the other three scenarios, since it could occur
in any one of the other scenarios, although it is perhaps
less likely to occur in the case of concerted efforts than
that of business-as-usual. It is intended to highlight the
consequences of a surprise event, such as an abrupt change of
global climate as a result of an unforseen change of the
oceanic circrtlation.
The Responses Limitation refers to steps taken to reduce
emissions. Anticipatory adaption refers to steps taken before
effects occur, while forced adaptation occurs in response to
physical and biological impacts. Residual costs are absorbed
costs, i.e., those for which adaptation steps are not, or
cannot be, undertaken. These will largely be costs involving
externalities such as the global commons, unmanaged ecosys
tems and human suffering_ It is worth noting that g_lt.i.mat_E::l_y
.£.dru?_:t9 t .i.mL s tx_g._t._e g i __ e q ____ w i 1 L _ _hg_y_~_j;.g__J:;gi_J .. §..P_lg._g__e Q.__j;Jy__j__i mi tat :i,.9 n
_g;j;._;r_e_t_~g.i§.§_,_ ___ s iJlQ_E2_ __ S!!l .... 11J.lJ .. im;ij:;,_~_q _w_c;x.m.i.D-J.L .... W.9.1-l.l~L_;:;;_go!_le .L_QK_l9:t er
.b .. !fi~_QJ.l1.~- i n_t9l er ciQ_l..~._p o ___ m_g_t_:t_~_:r_J:l9.Y.:Lffi.lJ.QQ_j,..§.__e_Q..~n t on_£ da2ta t ion .
29
Also, limitation strategies cannot totally avoid future build
up of GHGs Ji.QffiSL__aq.§._p__:tat.i..o!L __ t7.il_l .. J?.~LX..§...9...\lired-L.-~-~P.e£JalJ_y__e,_§ ___ Q
_res u l__t_ __ Q f_ . .-:t11.§..... em i_§.§..i...QJL!?. . .....t.hat.._Jl-?. V.§. __ q_:l,~:·e a_<i'l:.. .. .Q c 9.JJ!'X_©._Q . A b a 1 an c e
limitation and adaptation will be required. >> >0••0'0>0>hoo,.OoOoOooOo,>000>""''"'"''•'00'0•>""' '"''"'"""'"''"'"'''"'''''''''"''""'''''''''''"MO"'''''''"''"•''''''"'''"'''''''" """"'''"''"'''"'''''"'''''''''"'''"'''"""''"'''"''""""'""'"''" ''''"'''"'' ............................................ ············ .............................. ,.-............... ........ ....... . ..... ..... ........................ .. ....... . ........... .
. FIGURE 2.
Relative costs of four different types of effort undertaken in three different strategies for responding to climatic change. The relative costs are indicated by w,x,y,z. In addition, the relative costs of a surprise occurence are shown. ---------r-----------
LIMITATION --------------------------r--------ANTICIPATOR~ FORCED RESIDUAL
(reduce emissions)
I Business as Usual I w
Moderate Efforts I ww
Concerted Efforts t wwwww
--------- -----------Surprise
- - - - -- - - - -Comments
= = = = = = •= long lead time
ADAPTATION j ADAPTATION
(primarily adjust to I (absorbed effects) 1 costs)
XX
xxxx
XX
---------·---varying
lead time
yyyyy
YYY
y
YYYYYYY
- - - - -- - - - -no lead time
zzzzz
?
z
zzzzzzzz
- - - -- - - -
"''''''''"u""'''"'.,'"'"'"'""'''"'"'""''"'"'"''""'"''"'"'"'''''"'''..,'''-"'' .. '"'"""""''""'''' ..... ''''"''''"''''"''""''""'''"'''"''"'''-'''''"''"'"''""''""''''''"''"'''""'' .. "''"''''""''""""''""''''..,'''"''"'"'''"'''''Wiooooo"o""''""'"'''""'''"'"'"'••••o"o"o ......................................................................................................................................................................................................................................................................................................................................................
Units of Costs Different types of costs (symbolized by the
use of w, x, y, and z) are used to emphasize that the costs
of limitation and of anticipatory adaptation can be monet
ized. Forced adaptation, however, would involve both monet
ized costs (e.g., costs of rebuilding a flooded village) and
unmonetized costs (e.g., loss of human life, environmental
damage). Residual costs will be almost entirely unmonetized.
The symbols are given only to indicate relative costs
going down a column. In the absence of more data, it is not
30
possible to compare across the rows. The costs in the
limitation column would be JJ1.Y.S:_$ _ _:tm~n._t costs that could become
net positive investments (i.e., generators of profit). For
example, many end-use efficiency improvements could pay for
themselves in a few years. Different measures to reduce
emissions would have different long-term cumulative costs. If
"concerted efforts" concentrated on increases of energy end
use efficiency the cumulative costs would be different than
if ··concerted efforts" concentrated on a restructuring of the
energy supply system and large-scale introduction of solar
or nuclear energy. Costs for adaptation would in many cases
involve bills to repair damage.
Geographic Scale of Action and Analysis Limitation
strategies will generally be implemented at the national
level with agreements to undertake limitation being taken at
international levels., On the other hand, adaptation strat
egies do not require international agreements, although for
some adaptation alternatives an agreement could be benefi
cial, e.g., in the case of international trade agreements.
Adaptation strategies will be implemented at local levels and
to a lesser extent at the national level.
It is clearly impossible to analyse adaptation costs on
a global level and probably even at the national level for
the large! countries. Comparisons of local adaptation costs
and national limitation costs could best be made on the
basis of regional studies, where a fraction of the national
cost for limitation is assigned to the region on the basis of
the contribution of the region to GNP, total energy demand,
GHG emissions, or some other appropriate measure.
Residual costs, as pointed out above, will not be
monetized. However, it will be necessary to characterize at
least those involving unmanaged ecosystems and the global
commons on a global basis.
Timing Issues The costs shown as
studied for the period 6£ roughly
w, x, and y should be
1990 - 2050, perhaps by
:31
decade, with the aggregate costs integrated over time. This
length of time is required to get a preliminary measure of
net costs (of, for example, investments in new energy
technologies) as opposed to initial costs.
Costs for Developed and Developing Countries There are major
differences among the scenarios regarding the relative costs
to be met by different countries. Given the present knowledge
of costs and of expected climatic changes it is not possible
to make reliable intercomparisons of costs of different
scenarios in different countries. At a crude level of
aggregation, the majority of the costs of the ''Concerted
Efforts'' scenario would be borne by developed countries in
the form of research, development and deployment of new
energy technologies, development of alternatives to CFCs and
GHG abatement techniques. Similarly, in the ''Moderate
Efforts'' scenario, where substantial effort would go into
anticipatory adaptation, developed countries will spend more
money and make most attempts at anticipatory adaptation,
since it is generally these countries that have the scien
tific and technical knowledge and the bureaucratic and
management resources to implement the needed changes and the
economic resources to pay for them. International assistance
would be needed to pay for anticipatory adaptation in many
developing countries, so additional bilateral and multi
lateral funding would be required.
"Forced Adap·tation" costs in both the "Moderate Effort"
and "Business-as-Usual" scenarios would be larger in many
developing countries, to the extent that they will have been
less able to carry out "Anticipatory Adaptat~ion" . The same is
true for the "Residual Costs". Here again, many developing
countries would probably have more costs, to the extent that
they had not been able to carry out "Forced Adapt.ation".
Thus, in Figure 2 the developed countries will pay the
most in the left and lower boxes, while the burden shifts
more towards the developing countries as one moves from left
to right and from bottom to top in the figure. From this
:32
perspective, ·the "Business-as-Usual" scenario looks worst
from the point of view of the developing countries, while the
"Concerted Effort" scenario looks the best.
4.5 POLICY RESEARCH REQUIREMENTS In the previous sections several items were discussed
that require further policy research in the immediate future.
These items are listed in the following paragraphs, with some
discussion of their relevance. Research on these items should
be started now so that preliminary results can be reviewed at
the Second World Climate Conference in 1990.
When to act ? The entire issue of increasing concentra-tions
of greenhouse gases and the resulting climatic change
involves a high level of uncertainty. If decision-makers were
to wait until the scientific uncertainty is "acceptably"
small, most policy responses would be too late. Further
investigation is, therefore, needed regarding the main
factors involved and the appropriate time for action.This
will involve analysis of ·the rate at which scientific
uncertainty can be expected to decrease compared with the
rate at which GHG concentrations are increasing. An alterna
tive approach to this question would be to ask "Why haven't
we acted so far ? Why have limitation strategies that are
claimed to be "feasible" not been implemented '?"
What are the policy alternatives and how much will they
cost ? The costing
(pages 27 to
framework discussed in
31) should be developed
the previous section
and applied on an
experimental basis in order to evaluate its utility. For the
purposes of policy development it would also be useful if the
costing of scenarios could be used to provide an estimate of
the aggregate effects of climatic change on a single region.
Further, there is a need for a reexamination of the
question of discounting within the context of climatic change
and at the implications of transnational and transgeneration
al transfers of costs.
213
What institutional mechanisms are required for developing
policies in response to climatic change ?
What role can bilateral or multilateral agreements
realistically be expected to play in developing policies for
limiting or adapting to climatic change ? How can we deal
with the urgency of the problem ? How can developed and
developing countries begin to develop a joint
~limatic change ?
response to
Targets Detailed studies are now required to examine the
relationships between GHG emissions and environmental
effects, with a view to setting targets for both. The
emissions rates of all GHGs must be made intercomparable by
using, for example, t.he concept of the "C02 equivalent"
(i.e., expressing the amount of each GHG in terms of the
amount of C02 that would produce the same radiative effect).
This would allow a total emissions picture to be obtained in
warming terms. Likewise, all reliably quantifiable indicators
of GHG-induced environmental change should be analysed,
especially rates of temperature and sea-level change.
Ideally, the management steps that could be taken if enough
information is available are: first, determine the target
(e.g. rate of global surface temperature change) that should
be reached if large-scale environmental and social problems
are to be avoided; second, specify the changes of rates of
GHG emissions that would be needed to reach this target;
third, regulate GHG emissions so that the environmental
target can be reached. The utility of absolute temperature
targets over a specified period of time should also be
considered. Once a target is agreed upon, the relative
weights given to adaptation and limitation strategies can be
settled and the decision of "when to act" could be made.
What can we learn from previous experience ? In several
respects the p~oblem of climatic changes resulting from
emissions of greenhouse gases is unique. Although the
emissions of these gases are distributed unevenly in time and
:34
space, the atmosphere rapidly spreads the trace gases evenly
throughout the globe. The resulting climatic changes are
expected to be unevenly distributed but it is not possible at
present to make reliable predictions of regional changes of
climate. One aim of policy research should be to review the
development of other international agreements (e.g., the Law
of the Sea, the Ozone Convention) and ascertain their utility
as models for the development of policy responses to changing
climate.
35
Section 5
DEYE.LQ.I'ING .. J~QJ,~_lQ_l.E~L-~OJL..RE.P.f.QN'J/lNG .... TQ_. CJd.ll11iT l C. .. CHAN'S,lE.
5.1 POLICY ACTIONS
In discussing how to develop policies for responding to
climatic change the participants at the Bellagio workshop
were guided by four sets of considerations:
First, in spite of uncertainties about the scale and
speed of climatic change and the factors whicl1 affect it, it
is clear that the common assumption underlying many dec-
---i-s--:1-ons in the social and economic sphere stil1 is that past
climatic data are a reliable guide to the future. This
assumption is no longer valid. If present trends continue,
climatic change will be more rapid in the future than it has
been in the last few millennia. Lead times for many of the
measures needed to deal with accelerated climatic change are
long.
Secondly, the participants emphasized the relationship
between the issue of climatic change and a number of other
issues, above all in the fie1d of environment and development
(for example. the increase in chlorofluorocarbon concentra
tions in the atmosphere acts both to decrease the amount of
ozone in the stratosphere and to increase the greenhouse
effect in the lower atmosphere). The report of the Brundtland
Commission has examined the ramifications of these numerous
interconnections. The significance of the difference in
regional effects should not, however, be allowed to detract
from the emphasis on the problem as a whole and the response
of the international community as a whole in facing it. Still
less should it encourage any attempts to divide countries or
regions into "winners" or "losers". This is not a ··zero-sum
game. Unless action is taken, it could be a negative sum ~ame
of highly uncertain proportions.
36
Thirdly, the participants looked at policies in response
to cl imat.i.c change under three headings: "Limitation", i.e. ,
measures to slow or reverse the growth of greenhouse gas
ccmcentr~ations in the at.mosphere; "Adapt.ation", i.e. ,
adjusting the physical environment or our ways of using it to
reduce the consequences of a change in cl imatJe; and "lnst.i ~tu-~
tional" changes, which include the measures necessary for the
world to organize itself to prepare and take action. A prudent policy Hill require a combination of all three
measures. They are, of course, interdependent in a number of
ways.
FourtJhly, the participants looked at policy response
with regard to several criteria - as a means of helping to
j11dge what sort of actions are required. First, there are
actions which are already identified and can be pursued
forthwith. Further. there is an urgent need to identify and
clarify the areas in which policy or scientific research is
required. There is a need to strengthen the conceptual
framework for dicussion of the problem and hence of the
remedial action required. There is an overarching demand for
increasing awareness Horldwide of all the problems posed by
GHG emissions and of the necessity for adopting measures to
tackle them.
37
5.2 PRIORITIES FOR ACTION
There are many longer-term actions that will be required
in order to ensure appropriate responses to climatic changes.
The actions that are listed in this section are those tha·t
should receive priority now because several of the responses
to climatic change could be made using institutional mechan
isms that already exist. For this reason they have been given
high priority, since they could be introduced without delay.
the rate of global temperature change that would occur if
current trends of GHG emissions were to continue (see Figure
la) is large compared with observed historic changes and
would have major effects on ecosystems and society. For this
reason, a coordinated international response seems inevitable
and rapid movement towards it is urged.
I mme d i.a.t.§_At.§~.tg_jJ,m.iJL.-GH(;i __ ..i,nc t:e..9.§_e_s__.iiL.the _g_t..mo §.I?hSlX.§
_Ll..LQ.z..Qne._j?roto_gol The Protocol on Substances that Deplet;e
the Ozone Layer should be approved and implemented without
delay. The protocol should be ratified as a matter of urgency
and after expedited scientific review consideration should be
given to acceleration of the schedule for reductions of CFC
emissions and eyentual elimination of emissions. This step
would be important not only for ozone layer protection but
also for greenhouse gas limitation.
ti.t_Energy_ Polici.sl.§ Governments should immediately begin
to reexamine their long-term energy strategies with the goals
of achieving high end-use efficiency, reducing multiple forms
of air pollution and reducing C02 emissions.
Research and development relevant to these issues,in
particular the development of alternative (non-fossil) energy
systems, must be greatly intensified.
.LaLFM.§Jit. __ _f_Q_li.Qll~ Deforestation is a source of carbo~
dioxide and other greenhouse gases.
deforestation in both tropical and
through locally appropriate action
Measures to reduce
extratropical areas
plans are already jus-
:38
tified by the consequences of deforestation for soil erosion,
drought, flooding, and energy and agricultural resources.
Some initiatives have already been taken to limit deforesta
tion. The contribution to greenhouse gases in the atmosphere '
is an additional reason for measures to counter deforesta-
tion.
The expansion of the forested area of the earth provides
many benefits, including the provision of a system for
absorbing atmospheric C02.
In general, the role of the forests in the GHG issue
points to a need for improved forest management throughout
i~hE=J world.
L4J _____ .Q:tJ:J..5l:r ...... 'l.'Xs.Q.~----G..9:.e.~S Measures should be undertaken to
limit the growth of non-COz GHGs in the atmosphere and to
avoid industrial and societal actions which unduly contribute
to such growth. Some measures could be implemented now.
Others need only a small amount o.f addT"T.-ional research and
development to evaluate their utility. Some require con
siderable additional study. The first category includes the
tapping of methane emissions from solid waste landfills for
energy production and the further control of CO, NOx and
hydrocarbon emissions from combustion sources to limit growth
in methane and ground-level ozone. The second group includes
limitation of nitrous oxide emissions through combustion
controls and through modification of type and method of
fertilizer application. The third category includes methane
emissions limitation through altered agricultural practices.
Research and development of these measures should be sup
ported now.
Immediate -~.:tslp_g_to._ limit th.~.-impa..Q_:L...Qi_ . .S..§9.::-..l.§..vel_..rj,se.
L~.l_Ri Y..e~. __ Es_t_y,_g.rin_~_ .. __ an_<i._Coas:t.al ____ Zone_Pol,Jgies Interna-
tional unions of geographic, coastal and geodetic and soil
sciences and/or governmental and intergovernmental agencies
should develop geographic information systems to. identify
areas vulnerable to sea-level rise, to the consequences of
3H
river regulation and to intensified land-use. Already there
are ongoing activities
UNEP. Planning for large
of this kind under the auspices of
new industrial, tourist and urban
installations near the sea should allow for the risks of sea
level rise.
Im.m~d.l.a:t.liL . .§.t.~.2.§ ____ t.9. .... i.m:R:r..QY_§.._ .. JJn4§:r.§ . .t_g._ndip.g_ .. g.f ____ th~ __ g;r;:e_~nhQY§.~
.§f.f~<;;rt .. -~nd.. .. QP.ti on~_f.g_r ____ ~_~g_li_ng_witJL.i.t.
iJU _________ fQJJ,_oy_.R_§..s~-q_r_Q..h ... Re . .9JJ..i.:r.~m.~n:t.s A number of institutions
already exist that should be actively encouraged to carry out
the policy research that was identified at the Bellagio
meeting. This research should be carried out simultaneously
by governmental and intergovernmental groups at an interna
tional level and by national and international governmental
and nongovernmental organizations.
Policy and scientific research should investigate
further the utility of particular goals as management tools.
An environmental goal expressed in terms of a rate of change
of temperature or sea-level is easy to relate to observed
historic rates of change. Such an environmental goal is
related to the ambient concentration of greenhouse gases
(expressed in terms of C02 equivalence) and thus to the
emissions. For each of these, regulatory targets need to be
defined. This would help to keep the risks associated with
climatic change within acceptable bounds.
Priority should also be given to the development of
methods that could provide useful estimates of the costs and
benefits of various scenarios. Further, an important research
topic would involve an analysis of the various strategies for
the limitation of emissions of GHGs to estimate how much
limitation particular strategies could provide within certain
timeframes. This would enable a more quantitative intercom
parison of the strategies .
..UJ_J1on i tor i n_g_j'_o r mode ll__i.n_g_ an<:t ___ d§.tec:t i_o_:n_Q.f __ ....Q_l i_mg_t__.i. _ _g ___ Qhg_:g._g_~
The problem of significant climate warming calls for a
considerable increase in global monitoring activities and the
40
further development of climate models to improve our under
standing of and to reduce uncertainties about the extent of
regional and global climatic changes and their impacts on the
environment and major socio-economic sectors.
It is, therefore, recommended that WMO/WCP (World Meteor-
ological Organization/World Climate Programme) and UNEP/GEMS
(United Nations Environment Programme/Global Environmental
Monitoring System) carry out a joint study of:
What new climate observing system activities are
required for monitoring the changing global
climate ?
What basic emissions data on GHGs need to be
continuously monitored and archived globally ?
What activities are required for monitoring the
consequences of the changing climate ?
What advantages and opportunities exist for
simultaneous integrated multi-media monitoring
of climate and its impacts on biota and ecosys
terns at selected interdisciplinary research
sites ?
The IOC through the Global Sea Level Observing System
should give urgent attention to strengthening the monitoring
of sea-level changes worldwide.
lJU_Scient.ific Re§eg,rQ.b. ___ _ Much of the scientific research
that is required because of remaining uncertainties about
climatic change will be organized nationally and carri~d out
at individual institutions. However, increased support for
scientific research and assessment at the international level
should be given high priority.
The World Climate Programme (WCP) is jointly supported
by ICSU, UNEP and WMO. This programme is the focus for the
further international assessment of both basic research
41
issues concerning global climatic change and questions about
climatic impact. The World Climate Research Programme (WCRP)
1s an important component of the WCP, because the assessment
of possible or likely future climatic changes rests on a
comprehensive understanding of the global climate system.
Similarly, the new research programme IGBP (Internation
al Geosphere Biosphere Programme), initiated by ICSU,
addresses the scientific problems that we are now ~onfronting
when trying to understand the biological and geochemical
interactions that contribute to future climatic change and
are of importance for understanding climatic impacts.
In all cases, the scientific research on matters related
to the GHG issue should be planned with due consideration of
policy requirements.
lns.t.i.tJJt.i9.miA .. LJ!,e,_q Yi .. :r.e.m.e_nts
.L~U .. .'r.b_~_ ....... A.dvi .. SQ:r.Y. ... G;rQJ;t_p __ ... _Qn _ _Gr.~.§.nhQ.IJ.~HL .. _ . .G_g_s_~_s_ __ (_A,G.G.G1 The AGGG
was established by WMO, UNEP and ICSU in response to the
Villach 1985 conference on greenhouse gases, climatic change
and ecosystems (the members of the AGGG are listed in
Appendix 3). The recommendations of the Bellagio meeting were
presented to the AGGG at their meeting in Paris in December
1987. The AGGG recommended the setting up of three working
groups to carry out some of the necessary policy research. It
is important that financial support is provided to carry out
this work and to expand the activities of the AGGG.
Ll..Q.L ... Q:tb§> .. :r.. ____ !_n_g_tJ._:tJJ..ti9J1.§___________________ Organizations, including the
intergovernmental mechanism to be constituted by WMO and UNEP
in 1988, should examine the need for an agreement on a law of
the atmosphere as a global commons, as was developed in the
Law of the Sea, or the need to move towards a convention
along the lines of that developed for ozone.
ilJJ .... ..C.9n.t~r~n_g_e_.§ ______ _ The development of policy responses to
climatic change would be facilitated if the recommendations
of the present Report were considered and developed through-
42
<:mt a series of subsequent meeting·s. In June 1988 the
Canadian Government will host a World Conference on The
Changing Atmosphere. The WMO, with ICSU and UNEP is organiz
ing the Second World Conference, which will be held in Geneva
in ;Spring H~ 90 .
.tl2J _.P.rQt.OG.QlS.. __ The World Commission on Environment and
Development (the Brundtland Commissic•n l w;;:,-1s established
following a resolution of the UN General Assembly and
completed its report in February 1987. The resolution of
the Brundtland Commission report at the 1987 UN General
A~:>SE3nb ly is to be welcomed. It ~:;hould be storongly recommended
that an Auxilliary Resolution dealing with Global Change
should be brought to the next UN General Assembly with a list
of actions that have to be taken. research that needs to be
done etc.
_(J_Q .. LJ_:rr!,R_l._~_me_rrt.9.t..:i.9Jl A mechanism. perhaps in the form of
a professional secretariat, should be established to help to
ensure that the recommendations of the Bellagio workshop are
implemented and to coordinate the necessary policy and scien
t.if ic research.
43
APPENDIX 1
DEVELOPING POLICIES FOR RESPONDING TO FUTURE CLIMATIC CHANGE Villach, Austria
28 September - 2 October 1987
LIST OF PARTICIPANTS
D. Abrahamson University of Minnesota MINNEAPOLIS, MN 55455 USA
M.J.A. Antonovsky IIASA Schlossplatz 1 A-2361 LAXENBURG Austria
J. Bardach East West Center 1777 East West Road HONOLULU, Hawaii 96848 USA
R. Baumann Federal Environmental Agency Waehringer Strasse 25a A-1090 VIENNA Austria
E. Brown-Weiss Georgetown University Law Center 600 New Jersey Avenue NW WASHINGTON, DC 20001 USA
M .J . Chadwi ck Beijer Institute Royal Swedish Academy of Sciences Box 50005 S-104 05 STOCKHOLM Sweden
R. Christ Federal Ministry of Environment, Youth and Family Radetzkystrasse 2 A-1030 VIENNA Austria
W.C. Clark Kennedy School of Government Harvard University 79 Kennedy Street CAMBRIDGE, MA 02138 USA
P. Crosson Resources for the Future 1616 P. Street NW WASHINGTON, DC 20036 USA
M.B. Davis Department of Ecology and Behavioural Biology University of Minnesota 38 Church Street SE MINNEAPOLIS, MN 55455 USA
E. Degens SCOPE/UNEP International Carbon Centre University of Hamburg HAMBURG 2000 Federal Republic of Germany
R.E. Dickinson National Center for Atmospheric Research P .0. Box 3000 BOULDER, CO 80307-3000 USA
H. Dobesch Central Institute of Meteorology and Geophysics Hohe Warte 38 A-1190 VIENNA Austria
D .J. Dudek Environmental Defense Fund 257 Park Avenue South NEW YORK, NY 10010 USA
J .A. Edmonds Battelle Pacific Northwest Laboratory 2030 M. Street NW WASHINGTON, DC 20036 USA
R. Fantechi Commission of the European Communities 200 Rue de la Loi 1040 BRUSSELS Belgium
J. Firor National Center for Atmospheric Research P.O. Box 3000 BOULDER, CO 80307-3000 USA .
P.H. Gleick Energy and Resources Group Building T-4, Room 100 University of California BERKELEY, CA 94720 USA
G.T. Goodman Beijer Institute Royal Swedish Academy of Sciences Box 50005 S-104 05 STOCKHOLM Sweden
L.D.D. Harvey Department of Geography University of Toronto 100 St. George St. TORONTO, Ontario Canada M5S 1A1
G.P. Hekstra Ministry of Environment (VROM) P.O. Box 450 NL-2260 LEIDSCHENDAM MB Netherlands
J.E. Hobbie Ecosystems Center Marine Biological Laboratory WOODS HOLE, MA 02543 USA
44
J. Jaeger Eichenstrasse 2A 8152 Feldkirchen-Westerham 2 Federal Republic of Germany
L. Kristoferson Beijer Institute Box 50005 S-104 05 STOCKHOLM Sweden
J.A. Laurmann Gas Research Institute 8600 W Bryn Mawr Avenue CHICAGO, IL 60656 USA
J.A. Mabbutt Emeritus University of New South Wales RMB 218 8 Wattamolla Road BERRY, New South Wales 23535 Australia
W.H. Mansfield Deputy Executive Director United Nations Envi ronu1ent Programme P.O. Box 47074 NAIROBI Kenya
G. McKay Environment Canada 4905 Dufferin Street DOWNSVIEW, Ontario Canada M3H 5T4
M. Oppenheimer Environment Defense Fund 257 Park Avenue South NEW YORK, NY 10010 USA
M. Parry Atmospheric Impacts Research Group Department of Geography University of Birmingham P.O. Box 363 BIRMINGHAM B15 2TT England
J.C. di Primio Kernforschungsanlage Juelich JUELICH 5170 Federal Republic of Germany
Ren Mei-e Department of Geography Nanjing University NANJ ING China
E.F. Roots Department of Environment 10 Wellington Hull OTTAWA Canada K1A OH3
N.J. Rosenberg Resources for the Future 1616 P. Street NW. WASHINGTON, D.C. 20036 USA
E. Sal ati CENA-USP Rua Dr. Paulo Pinto 1251 PIRACIACABA Brazil-13400
W. Sassin Kernforschungsanlage Juelich Postfach 1913 JUELICH 517 Federal Republic of Germany
I. Smith IEA Coal Research 14-15 Lower Grosvenor Place LONDON SW1W OEX England
A.M. Solomon I IASA Schlossplatz 1 A-2361 LAXENBURG Austria
H. O~Reilly Sternberg University of California Department of Geography 501 Earth Sciences Building BERKELEY, CA 84720 USA
N. Sundararaman World Meteorological Organization Case Postale no. 5 CH-1211 GENEVA 20 Switzerland
45
D. Tirpak US EPA Office of Policy Analysis 401 M. Street SW WASHINGTON, DC 20460 USA
W. Terhorst Kernforschungsanlage Juelich Postfach 1913 JUELICH 5170 Federal Republic of Germany
P. Usher UNEP P.O. Box 47074 NAIROBI Kenya
P. Vellinga Del ft Hydraulics P.O. Box 152 8300 AD EMMELOORD Netherlands
C.C. Wallen UNEP Consultant c/o World Meteorological Organization Case Postale no. 5 CH-1211 GENEVA 20 Switzerland
c. Weiss International Technology Management and Finance Inc. 6309 Crathie Lane BETHESDA, MD 20816 USA
P • B. Wi 11 i ams Philip Williams and Associates Consultants in Hydrology Pier 35 The Embarcadero SAN FRANCISCO, CA 94133 USA
G.M. Woodwell Woods Hole Research Center 13 Church St. P.O. Box 296 WOODS HOLE, MA 02543 USA
l.\.8
APPENDIX 2
DEVELOPING POLICIES FOR RESPONDING TO FUTURE CLIMATIC CHANGE Policy Workshop Bellagio, Italy
9-13 November, 1987
A. Al-Hamad Arab Fund for Economic and Social Development P 0 Box 21923 13080 SAFAT Kuwait
J. Bardach East-West Center 1777 East West Rd. 25 Hawaii 96848 U.S.A.
B. Bolin Meteorological Institute Arrhenius Laboratory University of Stockholm 106 91 STOCKHOLM Sweden
P. Bourdeau Environment and Non-nuclear Energy Sources Directorate General XII E Science, Reearch and Development Commission for the European Economic Community 200 Rue de la Loi 1049 BRUSSELS Belgium
J.P. Bruce World Meteorological Organization CP No. 5 CH-1211 GENEVA 20 Switzerland
W.C. Clark Kennedy School of Government Harvard University 79 Kennedy Street CAMBRIDGE MA. 02133 U.S.A.
P. Crutzen Department of Atmos. Chem. Max Planck Institute for Chemistry Faarstrasse 23 Postfach 3060 D-6500 MAINZ FR Germany
W. Degefu The National Meteorological Services Agency P.O. Box 1090 ADDIS ABABA Ethiopia
H. L. Ferguson Atmospheric Environment Service, Environment Canada 4905 Dufferin Street DOWNSVIEW Ontario M3H 5T4 Canada
G.T. Goodman The Beijer Institute Box 50005 104 05 STOCKHOLM Sweden
H. Goto Air Quality Bureau Environment Agency of Japan 1-2-2 Kasumigaseki Chiyoda-Ku TOKYO 1900 Japan
V. Hauff Bundeshaus D-5300 BONN 1 F.R. Germany
G.P. Hekstra Ministry of Environment p.o. Box 450 NL-2260 lEIDSCHENDAM MB The Netherlands
J. Jager Eichenstrasse 2 A 8152 FELDKIRCHEN-WESTERHAM 2 FR Germany
M. Lonnroth The Cabinet Office Rosenbad 4 103 33 STOCKHOLM Sweden
Sir P. Mars ha 11 Commonwealth Secretariat Marlborough House Pall Mall LONDON SW1Y 5HX England
J. Mathews World Resources Institute 1735 New York Avenue, N.W. WASHINGTON, D.C. 20006 u.s.A.
J. MacNeill Institute for Research on Public Policy 275 Slater Street Suite 500 OTTAWA K1P 5H9 Canada
W.H. Mansfield UN Environment Programme P.O. Box 47074 NAIROBI Kenya
W.J. Maunder New Zealand Meteorological Service P 0 Box 722 WELLINGTON New Zealand
V. Newi 11 U.S. Environmental Protection Agency 401 M. Street S.W. WASHINGTON D.C. 20460 U.S.A.
~~ 7
M. Oppenheimer Environmental Defense Fund 257 Park Avenue South NEW YORK N. Y. 10010 U.S.A.
C.C. Wallen c/o World Meteorological Organization 41 Guiseppe-Motta Case Postale No 5 CH-1211 GENEVA 20 Switzerland
G.M. Woodwell Woods Hole Research Center P.O. Box 296 WOODS HOLE MA. 02543 U.S.A.
48
APPENDIX 3
The Advisory Group on Greenhouse Gases
This Group was set up in response to the recommenda·tions of the Villach 1985 Conference on The Assessment of the Role of Carbon Dioxide and of other Greenhouse Gases on Climate Variations and Associated Impacts. The group advises WMO, UNEP and ICSU on matters relating to the greenhouse gas issue.
The members of the AGGG in December 1987 were:
F.K. Hare (Chairman) B. Bolin G. Golitsyn G.T. Goodman M.A. Kassas S. Manabe G.F. White
49
APPENDIX 4
Acronyms and abbreviations used in the report
AGGG
CFC
GEMS
GHG
ICSU
IGBP
IOC
UNEP
WCED
WCP
WMO
TWyr
The Advisory Group on Greenhouse Gases (see Appendix 3)
Chlorofluorocarbon. Chlorofluorocarbons are added to the atmosphere as a result of human activities. They act both to destroy the stratospheric ozone layer and add to the greenhouse effect.
Global Environment Monitoring System
Greenhouse gas
International Council of Scientific Unions
International Geosphere Biosphere Program
International Oceanographic Commission
United Nations Environment Programme
World Commission.on Environment and Development
World Climate Programme
World Meteorological Organization
Terawatt year. l Terawatt is the unit of energy
equivalent to l billion kilowatts (kW) or 1012
watts. lTW, if emitted continuously for a year is
l TWyr·. Using l TWyr/year is equivalent to burning
approximately l billion tons of coal annually.
5()
APPENDIX 5
Assumptions Made in Deriving the Emissions Scenarios
Current Tren.Q.._§_Scenario
Carbon Dioxide (C02): Scenario uses fossil fuel emissions from Reilly et al. (1987), Table 10. An additional 1.5 x 1015 gC/yr was assumed from deforestation, including both land use changes for energy and other purposes. The atmospheric retention rate (airborne fraction) was assumed to be 0.5.
Chlorofluorocarbons (CFC13, CF2Cl2): Scenario assumes that the recent CFC protocol is successfully implemented.
Methane (CH4): Assumes 1980 concentration of 1.65 ppm and the rate of growth of the concentration at 1.1% per year (current rate).
Nitrous oxide (N20): Assumes 1980 concentration of 0.3 ppmv and the rate of growth of the concentration at 0.8%/yr. (current rate).
Low Emissions Scenario
Scenario taken from Mintzer (1987).
Assumes high rates of improvement in end-use energy efficiencies, low costs of renewable energy technologies, high costs of fossil fuels,
Cheap substitutes for chlorofluorocarbons that do not affect the global radiation balance are found.
0.4%/yr rate of growth of atmospheric methane.
High Emissions Scenario
Scenario taken from Mintzer (1987).
Assumes low costs of fossil fuel using technologies.
High cost of renewable resources energy technologies.
Rapid deforestation
Collapse of the CFC protocol
2.3%/yr growth in atmospheric methane.
51
REFERENCES for Appendix 5
Mintzer, I.M., 1987: A Matter of Degrees. World Resources Institute, Washington D.C.
Reilly, J.M., J.A. Edmonds, R.H. Gardner, A.L. Brenkert, 1987: Uncertainty analysis of the IEA-ORAU C02 emissions model. The Energy Journal, 8 (3), 1-29.
52
APPENDIX 6
Assumptions Made in Assessing Effects on Mid.;...1atitude Forests
The lat,i tudina1 change in annual mean temperature in the middle latitudes is 100 - 150 km per oc. A change in temperature of 1 oC changes rates of respiration by 10 - 30%, occasionally more. An increase in temperature of 1 oC can be expected to increase rates of decay of organic matter in soils, swamps and bogs, increasing the rate of emission of C02 and CH4. The carbon released from such sources was not estimated in the present study but it is potentially large enough to affect the atmosphere significantly.
The reproductive success of trees would warming and would be conspiuous first along drier limits of the range of the species. A 1 century would produce measurable effects. threshold below which effects do not occur.
be reduced by a the warmer and o C warming in a
There is no
Populations of trees and other plants will suffer increased mortality in response to a climatic warming. Effects will be most conspicuous at the warmer and drier limits of distribution and on marginal sites. A warming of loC per century would produce measurable effects at these s~tes. Effects would be continuous for a warming.
Populations of commonly migrate sional species (Betula spp.) readily.
climax trees of major vegetation types at rates of 25-50 km per century. Succes
such as poplar (populus spp.) and birch often have lighter seeds that move more
The normal lifespan of forest trees in unmanaged temperate zone forests is more than 100 years.
The effects of pollution on forests were not considered but they can be expected to make the effects of climatic changes more severe.
53
APPENDIX 7
Background Papers prepared for the Villach Workshop
1. Transient Climate Response to a C02 Increase. L.D.D. Harvey, University of Toronto, Canada.
2. Uncertainties of Estimates of Climatic Change. R.E. Dickinson, National Center for Atmospheric Research, Boulder, Colorado, U.S.A.
3. Emissions Reduction and Control. J. Laurmann, Gas Research Institute, Chicago, U.S.A.
4. Greenhouse Warming and Changes in Sea-Level. J. Oerlemans, University of Utrecht, Netherlands.
5. Lags in Vegetation Response to Climatic Change. M.B. Davis, University of Minnesota, U.S.A.
6. The Ecology of Agriculture, Environment and Economy. D.J. Dudek, Environmental Defense Fund, New York, U.S.A.
7. The Biogeochemistry of the Sea and the Impact of C02. E.T. Degens, University of Hamburg, F.R. Germany.
8. Climate Change and Environmental Pollution: Physical and Biological Interactions. M. Oppenheimer, Environmental Defense Fund, New York, U.S.A.
9. Sea-level Rise, Consequences and Policies. P. Vellinga, Delft Hydraulics, The Netherlands.
10. Adapting Resources Management to Global Climate Change. P.Williams, San Fransiscc, U.S.A.
11. Can Markflt Mechanisms Ameliorate the Effects of Long-Term Climatic ChaLge ? C. Weiss, Maryland, U.S.A.
12. Climate Change, Intergenerational Equity and International Law. E. Bro~n-Weiss, Georgetown University, U.S.A.
13. Effects of Climatic Changes on Agriculture - And possible responses. M.L. Parry, University of Birmingham, U.K.
14. The Implications of Global Climatic Changes for International Security. P.H. Gleick, University of California, U.S.A.